Pole saw

ABSTRACT

An outdoor tool includes a powerhead, a tool unit powered by the powerhead, and a shaft assembly extending between the powerhead and the tool unit. The tool unit includes a transmission housing, a support plate, a guide bar adjustably supported by the support plate, a drive gear, and a chain circumscribing a portion of the drive gear and a portion of the guide bar, the drive gear operatively coupled to the powerhead. The tool unit further includes a tension adjustment mechanism for adjusting a position of the guide bar relative to the drive gear to increase and decrease a tension in the chain. The tension adjustment mechanism includes an adjustment screw, a threaded adjustment bolt, at least one adjustment gear, and a member coupled to the adjustment bolt and the guide bar. Rotation of the adjustment screw causes translation of the guide bar relative to the drive gear.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending U.S. Provisional PatentApplication No. 62/675,663, filed on May 23, 2018, the entire contentsof which is incorporated herein by reference.

FIELD OF THE INVENTION

The invention generally relates to outdoor tools, and, moreparticularly, to a pole saw.

BACKGROUND OF THE INVENTION

Outdoor tools, such as pole saws, are used to perform outdoor tasks,such as cutting tree branches.

SUMMARY OF THE INVENTION

In one aspect, an outdoor tool generally includes a powerhead, tool unitpowered by the powerhead, and an elongated shaft assembly extendingalong a shaft axis between the powerhead and the tool unit. The toolunit includes a transmission housing fixed to the shaft assembly, asupport plate coupled to the transmission housing, a guide baradjustably supported by the support plate, a drive gear rotatablysupported by the transmission housing, and a chain circumscribing aportion of the drive gear and a portion of the guide bar, the drive gearoperatively coupled to the powerhead for driving the chain about theguide bar. The tool unit further includes a tension adjustment mechanismfor adjusting a position of the guide bar relative to the drive gear inorder to increase and decrease a tension in the chain. The tensionadjustment mechanism includes an adjustment screw, a threaded adjustmentbolt, at least one adjustment gear intermeshed with the adjustment screwand the adjustment bolt, and a member coupled to the adjustment bolt andthe guide bar. Rotation of the adjustment screw rotates the adjustmentbolt and thereby causes translation of the guide bar relative to thedrive gear.

In another aspect, an outdoor tool generally includes a powerhead, atool unit powered by the powerhead, and an elongated shaft assemblyextending along a shaft axis between the powerhead and the tool unit.The tool unit includes a transmission housing fixed to the shaftassembly, a support plate coupled to the transmission housing, a covercoupled to the support plate wherein the support plate and cover definea cavity, a guide bar adjustably supported by the support plate, a drivegear rotatably supported by the transmission housing, and a chaincircumscribing a portion of the drive gear and a portion of the guidebar, the drive gear operatively coupled to the powerhead for driving thechain about the guide bar. The drive gear, a portion of the guide bar,and a portion of chain are housed in the cavity. The tool unit alsoincludes a lubrication system operable to lubricate the chain. Thelubrication system includes an oil reservoir, a pump drivingly coupledto the drive gear and in fluid communication with the oil reservoir andthe cavity, wherein operation of the pump pumps lubricant from the oilreservoir to the cavity. The lubrication system also includes an inlettube extending from the oil reservoir to the pump, a channel defined inthe cavity between the support plate and a surface of the guide bar, andan outlet tube extends from the pump to the cavity.

Other independent aspects of the invention may become apparent byconsideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an outdoor tool, such as a pole saw,including a pole saw attachment.

FIG. 2 is a perspective view of the pole saw attachment of FIG. 1.

FIG. 3 is another perspective view of the pole saw attachment of FIG. 1.

FIG. 4 is a side view of the pole saw attachment of FIG. 1.

FIG. 5 is another side view of the pole saw attachment of FIG. 1.

FIG. 6 is a top view of the pole saw attachment of FIG. 1.

FIG. 7 is a bottom view of the pole saw attachment of FIG. 1.

FIG. 8 is an end view of the pole saw attachment of FIG. 1.

FIG. 9 is another end view of the pole saw attachment of FIG. 1.

FIG. 10 is a side view of a saw head of FIG. 2.

FIG. 11 is another side view of the saw head of FIG. 2.

FIG. 12 is a top view of the saw head of FIG. 2.

FIG. 13 is a bottom view of the saw head of FIG. 2.

FIG. 14 is a perspective view of the saw head of FIG. 2.

FIG. 15 is another perspective view of the saw head of FIG. 2.

FIG. 16 is another perspective view of the saw head of FIG. 2, with acover removed.

FIG. 17 is a side view of the saw head of FIG. 2 with the reservoirremoved.

FIG. 18 is a cross-sectional side view of the saw head of FIG. 2, takengenerally along line 18-18 of FIG. 12.

FIG. 19 is another cross-sectional view of the saw head of FIG. 2, takengenerally along line 19-19 of FIG. 10.

FIG. 20 is another cross-sectional side view of the saw head of FIG. 2,taken along line 20-20 of FIG. 12.

FIG. 21 is another cross-sectional view of the saw head of FIG. 2, takenalong line 21-21 of FIG. 10.

FIG. 22 is another cross-sectional view of the saw head of FIG. 2, takenalong line 22-22 of FIG. 11.

FIG. 23 is a perspective view of a connecting portion of the pole sawattachment shown in FIG. 2.

FIG. 24 is another perspective view of the connecting portion of FIG. 2.

FIG. 25 is a cross-sectional view of the connecting portion of FIG. 2,taken along line 25-25 of FIG. 23.

FIG. 26 is a perspective end view of a connecting portion of a powerheadof the pole saw shown in FIG. 1.

FIG. 27 is another perspective end view of the connecting portion asshown in FIG. 26.

Before any independent embodiments of the invention are explained indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the following description or illustrated in thefollowing drawings. The invention is capable of other independentembodiments and of being practiced or of being carried out in variousways. Also, it is to be understood that the phraseology and terminologyused herein is for the purpose of description and should not be regardedas limiting.

The use of “including,” “comprising,” or “having” and variations thereofherein is meant to encompass the items listed thereafter and equivalentsthereof as well as additional items. Unless specified or limitedotherwise, the terms “mounted,” “connected,” “supported,” and “coupled”and variations thereof are used broadly and encompass both direct andindirect mountings, connections, supports, and couplings. Further,“connected” and “coupled” are not restricted to physical or mechanicalconnections or couplings.

Also, the functionality described herein as being performed by onecomponent may be performed by multiple components in a distributedmanner. Likewise, functionality performed by multiple components may beconsolidated and performed by a single component. Similarly, a componentdescribed as performing particular functionality may also performadditional functionality not described herein. For example, a device orstructure that is “configured” in a certain way is configured in atleast that way but may also be configured in ways that are not listed.

DETAILED DESCRIPTION

FIG. 1 illustrates an outdoor tool T, such as a pole saw, for use inperforming outdoor tasks such as cutting tree branches. The outdoor toolT includes an elongated shaft assembly 10 extending along a shaft axis14, a tool or saw head 18 at one end of the shaft assembly 10, and apowerhead 22 at an opposite end of the shaft assembly 10. The saw head18 includes a saw chain 26 for performing cutting. The powerhead 22generates a motive force to drive the saw chain 26 during operation ofthe outdoor tool T.

In the illustrated construction, the outdoor tool T includes a powerheadunit 30 and an attachment or tool unit 34, such as a pole saw attachment34, selectively and removably coupled to the powerhead unit 30 viaconnecting portions 38, 42 (FIGS. 23-27). The shaft assembly 10 includesfirst and second shaft segments 44, 46. The powerhead unit 30 includesthe powerhead 22, the first shaft segment 44, and the first connectingportion 38, and the attachment unit 34 includes the saw head 18, thesecond shaft segment 46, and the second connecting portion 42. In otherconstructions (not shown), the outdoor tool T is a standalone tool, sothat the saw head 18 and the powerhead 22 are not separable.

A first driveshaft segment 48 (partially shown in FIGS. 26-27) extendsaxially within the first shaft segment 44 along the shaft axis 14 and isdrivingly coupled to the powerhead 22. A second driveshaft segment 50(FIG. 18) extends axially within the second shaft segment 46 and isdrivingly coupled to the saw head 18. When the attachment unit 34 isattached to the powerhead unit 30, the first driveshaft segment 48couples to the second driveshaft segment 50 to drivingly transmit rotarypower from the powerhead 22 to the saw head 18.

A similar powerhead unit is described and illustrated in U.S.Provisional Patent Application No. 62/675,661, filed May 23, 2018,entitled “POWERHEAD UNIT FOR TOOL”, and in corresponding U.S. PatentApplication No.______, filed______, entitled “POWERHEAD UNIT FOR TOOL”,the entire contents of which is hereby incorporated by reference.

With reference to FIGS. 14-16, the saw head 18 includes a support plate54 (FIG. 16) and a guide bar 58 adjustably mounted to the support plate54. The guide bar 58 supports the chain 26 so that the chain 26circulates about a perimeter of the guide bar 58 during operation. Asprocket 62 (FIG. 16) engages the chain 26 and rotates about a sprocketaxis 66 to drive the chain 26 about the guide bar 58. A sprocket cover70 (FIG. 15) is coupled to the support plate 54 to retain and shield thecovered components (e.g., the sprocket 62, the chain 26, etc.) fromdebris and to inhibit accidental contact with moving components (e.g.,the sprocket 62, the chain 26, etc.).

The saw head 18 also includes a transmission housing 74 affixed to thesupport plate 54 and coupled to the second shaft segment 46 whereby thesecond shaft segment 46 is received therein. In the illustratedconstruction, the saw head 18 is fixed relative to the shaft assembly10. In other constructions (not shown), the saw head 18 may be supportedfor pivoting movement relative to the shaft assembly 10 about an axisgenerally perpendicular to the shaft axis 14 (e.g., about the sprocketaxis 66). A similar pivoting mechanism is described and illustrated inU.S. Provisional Patent Application No. 62/675,662, filed May 23, 2018,entitled “HEDGE TRIMMER”, and in corresponding U.S. Patent ApplicationNo.______ , filed ______, entitled “HEDGE TRIMMER”, the entire contentsof which is hereby incorporated by reference.

The second driveshaft segment 50 of the saw head 18 terminates withinthe gear housing 74. A transmission or gear assembly 78 (FIG. 19)transmits the rotary motion of the second driveshaft segment 50 to thesprocket 62 to circulate the chain 26 about the guide bar 58.

The gear assembly 78 includes an input gear 82 and an output gear 86.The input gear 82 is coupled to the second driveshaft segment 50 withinthe gear housing 74 for rotation about the shaft axis 14. The outputgear 86 is supported within the gear housing 74 by an output shaft 90for rotation about the sprocket axis 66. The input gear 82 engages anddrives the output gear 86 when the second driveshaft segment 50 isrotated by the powerhead 22. A portion of the output shaft 90 extendsthrough the support plate 54 and is drivingly coupled to the sprocket62.

The saw head 18 also includes an oil reservoir 94 (FIG. 14) and alubrication system 98 (FIG. 17) operable to supply lubricant (e.g., oil,etc.) from the oil reservoir 94 to the guide bar 58 and to the chain 26.Specifically, FIG. 17 illustrates the saw head 18 with the oil reservoir94 removed and depicts an oil pump 102 housed within the gear housing74. The oil pump 102 includes a pinion 106 (FIG. 19) that engages a wormgear 110 formed on the output shaft 90 (FIG. 19). The worm gear 110rotates during operation of the outdoor tool T to drive the pinion 106and operate the oil pump 102.

The oil pump 102 pumps lubricant through a fluid flow path 114 extendingfrom the oil reservoir 94, through the oil pump 102, to a flow pathoutlet 118 (FIG. 22) to lubricate the guide bar 58 and the chain 26. Theflow path 114 includes an inlet tube 122 (FIG. 17) extending from thereservoir 94 to a pump inlet 126 of the oil pump 102. An outlet tube 130extends from a pump outlet 134 of the oil pump 102, passes behind anadjustment bracket 138 (FIG. 17), and fluidly couples to a hollow tubemember 142 (FIG. 22) fastened to the support plate 54.

The tube member 142 extends through a flow path aperture 146 (FIG. 22)in the support plate 54 and terminates within a channel 150 definedbetween a flow path recess 154 in the support plate 54 and a surface ofthe guide bar 58. The channel 150 is fluidly connected to the flow pathoutlet 118. During operation of the outdoor tool T, oil flows throughthe flow path 114 from the reservoir 94 through the inlet tube 122, theoil pump 102, the outlet tube 130, the tube member 142, and the channel150 to the flow path outlet 118 to lubricate the guide bar 58 and thechain 26.

With reference to FIGS. 16 and 20, the saw head 18 includes a tensionadjustment mechanism 158 operable to adjust a tension force of the chain26 by adjusting the distance between the sprocket 62 and an end 160 ofthe guide bar 58. The tension adjustment mechanism 158 includes anadjustment screw 162 that extends through an axial slot 166 in the guidebar 58. The adjustment screw 162 also extends through a screw aperture170 (FIG. 19) in the support plate 54.

A first adjustment gear 174 is coupled to an end of the adjustment screw162 such that the two rotate together. A threaded adjustment bolt 178 issupported by the adjustment bracket 138 within an adjustment recess 182.A second adjustment gear 186 intermeshes with both the first adjustmentgear and the adjustment bolt 178. The first adjustment gear 174 engagesthe second adjustment gear 186 within the adjustment bracket 138, suchthat rotation of the adjustment screw 162 and the first adjustment gear174 thereby causes the second adjustment gear 186 and the adjustmentbolt 178 to rotate within the adjustment recess 182.

An adjustment stud 190 (FIG. 20) is threadably engaged with theadjustment bolt and fixedly coupled to the guide bar 58. The adjustmentstud 190 includes a threaded bolt aperture 194 (FIG. 21) that threadablyengages the adjustment bolt 178 within the adjustment recess 182. Theadjustment stud 190 extends from the adjustment recess 182 through a gap198 formed by the support plate 54 and engages a stud aperture 202formed in the guide bar 58. Rotation of the adjustment bolt 178 by theadjustment screw 162 causes the adjustment stud 190 to move forward orbackward within the adjustment recess 182 (i.e., away from or toward thesprocket 62).

With reference to FIGS. 16 and 19, a threaded guide bar stud 206 iscoupled to the support plate 54 and extends through the axial slot 166of the guide bar 58. When the sprocket cover 70 is mounted to the sawhead 18, the guide bar stud 206 also extends through a mounting aperture210 (FIG. 19) in the sprocket cover 70. A nut 214 fastens to the guidebar stud 206 to secure the sprocket cover 70 to the saw head 18. The nut214 is tightened to lock the guide bar 58 in position relative to thesprocket 62 and the support plate 54 and is loosened to unlock the guidebar 58 so that the tension of the chain 26 can be adjusted via thetension adjustment mechanism 158.

To adjust the tension, the nut 214 is first loosened (e.g., using a toolsuch as a wrench, socket and driver, etc.) to unlock the guide bar 58from the support plate 54. When the nut 214 is loosened, the guide barstud 206 continues to support the guide bar 58 but permits axialmovement of the guide bar 58 relative to the support plate 54. With thenut 214 loosened, the adjustment screw 162 is rotated to adjust thetension in the chain 26. Rotation of the adjustment screw 162 rotatesthe first adjustment gear 174, which causes the second adjustment gear186 and the adjustment bolt 178 to rotate. Rotation of the adjustmentbolt 178 causes the adjustment stud 190 to translate forward or backwardwithin the adjustment recess 182. Translation of the adjustment stud 190causes the guide bar 58 to translate with the adjustment stud 190 andrelative to the sprocket 62 due to the engagement of the adjustment stud190 with the stud aperture 202 of the guide bar 58 thereby adjusting thechain tension.

The adjustment screw 162 is rotated in a direction corresponding to thedesired tension adjustment. For example, in the illustrated constructionand referring to FIG. 16, the adjustment screw 162 is rotated clockwiseto translate the guide bar 58 away from the sprocket 62 and therebyincrease the tension in the chain 26. To decrease the chain tension, theadjustment screw 162 is rotated counter-clockwise to translate the guidebar 58 toward the sprocket 62. In other constructions (not shown), theopposite may be true—clockwise rotation of the adjustment screw 162 maydecrease the tension in the chain 26, and counter-clockwise rotation ofthe adjustment screw 162 may increase the tension in the chain 26.

With reference to FIGS. 23-27, the attachment unit 34 also includes thesecond connecting portion 42 that selectively couples to the firstconnecting portion 38 of the powerhead unit 30. In the illustratedconstruction, the second driveshaft segment 50 terminates at the secondconnecting portion 42 in a spline hub 218 (FIG. 25). When the powerheadunit 30 is coupled to the attachment unit 34, a spline 222 (FIGS. 26-27)on the first driveshaft segment 46 selectively engages and rotatablycouples to the spline hub 218, to transmit rotary power from the firstdriveshaft segment 48 and the second driveshaft segment 50 and,therethrough, from the powerhead unit 30 to the saw head 18.

As described in more detail in U.S. Provisional Patent Application No.62/675,661, filed May 23, 2018, entitled “POWERHEAD UNIT FOR TOOL”, andin corresponding U.S. Patent Application No.______, filed______,entitled “POWERHEAD UNIT FOR TOOL”, as shown in FIGS. 24 and 27, aretainer assembly (e.g., a quick-release mechanism 226 and a clampingmechanism 230) is provided between the connecting portions 38, 42. Theillustrated mechanism 226 includes a spring-biased button 234 with aprojection 238 engageable in a recess 242 (FIG. 24) to selectively andreleasably retain the connecting portions 38, 42. The connecting portion38 is formed with clamping flanges 246 engaged by a clamping actuator250 (e.g., a bolt and nut) to apply a clamping force to the connectingportion 42.

One or more independent features and/or independent advantages of theinvention may be set forth in the claims.

What is claimed is:
 1. An outdoor tool comprising: a powerhead; a toolunit powered by the powerhead; an elongated shaft assembly extendingalong a shaft axis between the powerhead and the the tool unit, the toolunit including a transmission housing fixed to the shaft assembly, asupport plate coupled to the transmission housing, a guide baradjustably supported by the support plate, a drive gear rotatablysupported by the transmission housing, and a chain circumscribing aportion of the drive gear and a portion of the guide bar, the drive gearoperatively coupled to the powerhead for driving the chain about theguide bar; and a tension adjustment mechanism for adjusting a positionof the guide bar relative to the drive gear in order to increase anddecrease a tension in the chain, the tension adjustment mechanismincluding an adjustment screw, a threaded adjustment bolt, at least oneadjustment gear intermeshed with the adjustment screw and the adjustmentbolt, and a member coupled to the adjustment bolt and the guide bar,wherein rotation of the adjustment screw rotates the adjustment bolt andthereby causes translation of the guide bar relative to the drive gear.2. The outdoor tool of claim 1, wherein the threaded adjustment bolt issupported by an adjustment bracket and coupled to the at least oneadjustment gear.
 3. The outdoor tool of claim 1, wherein the tensionadjustment mechanism further includes a guide bar stud coupled to thesupport plate and a nut engaged with the guide bar stud, whereintightening the nut locks the guide bar in a fixed position relative tothe drive gear and the support plate, and further wherein loosening thenut unlocks the guide bar to permit adjustment of the guide bar relativeto the drive gear.
 4. The outdoor tool of claim 3, wherein a cover iscoupled to the support plate and configured to shield the drive gear,and wherein the guide bar stud extends through a mounting apertureformed in the sprocket cover.
 5. The outdoor tool of claim 1, whereinrotation of the adjustment screw causes the member to move toward oraway from the drive gear.
 6. The outdoor tool of claim 1, whereinclockwise rotation of the adjustment screw causes the guide bar totranslate the away from the drive gear to increase a tension in thechain, and wherein counter-clockwise rotation of the adjustment screwcauses the guide bar to translate toward the drive gear to decrease atension in the chain.
 7. The outdoor tool of claim 1, wherein the membercomprises an adjustment stud threaded onto the adjustment bolt.
 8. Theoutdoor tool of claim 7, wherein the adjustment stud engages a studaperture formed in the guide bar.
 9. An outdoor tool comprising: apowerhead; a tool unit powered by the powerhead; and an elongated shaftassembly extending along a shaft axis between the powerhead and the toolunit, the tool unit including a transmission housing fixed to the shaftassembly, a support plate coupled to the transmission housing, a covercoupled to the support plate wherein the support plate and cover definea cavity, a guide bar adjustably supported by the support plate, a drivegear rotatably supported by the transmission housing, and a chaincircumscribing a portion of the drive gear and a portion of the guidebar, the drive gear operatively coupled to the powerhead for driving thechain about the guide bar, wherein the drive gear, a portion of theguide bar, and a portion of chain are housed in the cavity; and alubrication system operable to lubricate the chain, the lubricationsystem including an oil reservoir, a pump drivingly coupled to the drivegear and in fluid communication with the oil reservoir and the cavity,wherein operation of the pump pumps lubricant from the oil reservoir tothe cavity, an inlet tube extending from the oil reservoir to the pump;a channel defined in the cavity between the support plate and a surfaceof the guide bar, and an outlet tube extends from the pump to thecavity.
 10. The outdoor tool of claim 9, wherein the tool unit includesan output shaft coupled to the drive gear.
 11. The outdoor tool of claim10, wherein the pump includes a pinion that is drivingly engaged withthe output shaft of the tool unit.
 12. The outdoor tool of claim 11,wherein the output shaft includes a worm gear drivingly engaged with thepinion.
 13. The outdoor tool of claim 12, wherein the shaft assemblyincludes a first driveshaft segment drivingly coupled to a seconddriveshaft segment to transmit rotary power from the powerhead to thetool unit, and wherein the second driveshaft segment is coupled to aninput gear that engages and drives an output gear supported by theoutput shaft.
 14. The outdoor tool of claim 9, wherein a fluid flow pathextends from the oil reservoir to a flow path outlet formed in the guidebar.
 15. The outdoor tool of claim 14, wherein during operation of thelubrication system, oil flows along the flow path from the oil reservoirthrough the inlet tube, the pump, and the outlet tube, to the cavity.16. The outdoor tool of claim 9, wherein the lubrication system furtherincludes a tube member extending from the outlet tube to a channel, thechannel being fluidly coupled to the cavity.
 17. The outdoor tool ofclaim 16, wherein the tube member extends through a fluid flow pathaperture in the support plate and terminates within the channel.
 18. Theoutdoor tool of claim 17, wherein the outlet tube extends from the pumpto the tube member.
 19. The outdoor tool of claim 9, wherein the toolunit includes an adjustment bracket coupled to the support plate. 20.The outdoor tool of claim 19, wherein the outlet tube passes between theadjustment bracket and the support plate.